Cells, tissues, organs, and organisms that are deprived of appropriate blood flow undergo ischemic damage. Traditional methods of reducing ischemic damage involve perfusing affected tissues with oxygen, but this procedure can cause significant tissue damage and can result in serious and/or permanent injury, such as brain damage during stroke or cardiac arrest.
Attempts have been made to reduce ischemia-reperfusion injury (IRI) by inducing tissues and organs to enter a reduced metabolic state. In the context of living tissues being preserved for transplant or grafting, one common method for reducing their metabolic activity is by immersing tissues or organs in a physiologic fluid, such as saline, and placing them in a cold environment. However, such methods cannot be relied upon for extended periods, and the success of organ and tissue transplant and limb reattachments remains inversely related to the time the organ, tissue or limb is out of contact with a living organism. Accordingly, there is a need for improved methods of preserving organs, tissues, limbs and other biological materials.
Separately, oxygen deprivation can also occur in living organisms when the lungs are improperly functioning or not functioning at all. One approach to improving oxygenation in patients is through the use of ECMO, in which venous blood is extracted from the patient, passed through a membrane oxygenator, and then returned to the patient. The ECMO system may include filters or other components which are used to remove blood clots and other biological materials that may need removal before blood is reintroduced into the patient thereby avoiding clogging of the ECMO system, in particular clogging of the membrane oxygenator. There is a need to improve existing ECMO systems and methods to avoid this clogging.